Hey guys, I had a very large exhaust leak around my exhaust manifold to the head, and the flange to the pipe.

I replaced both.

I went to fire it up, and it will fire, run for 2-3 seconds, and sputter down and die.

I can start the truck with the pedal pressed (at any position), and it will rev up, but only for about 2-3 seconds and then it sputters down and dies.

I haven't done any work since the last start/run besides the manifold gasket, so I'm not certain where the problem could be, too much back-pressure now?

I tried disconnecting the battery first thing (for about an hour) to re-set the computer and hopefully remove any learnt air/fuel adjustments.

Any ideas guys? Where should I start?

 

Make sure your AFM wire is connected.

 

or make sure you dont have any intake leaks...I did some work on mine and tore the boot that attaches to the throttle body...had same problem with mine though. Any intake system leak (between AFM and throttle body) will cause that. Not saying its the only thing, but it is one certain thing.

 

Thanks guys.
Terry was spot on, got home from work, multimeter in hand. Noticed the afm clip was only half plugged in. Problem solved.

I guess between climbing into the engine bay over the tire (4" lift on 39" swampers) I knocked it loose.

Thanks again guys, you rock!

 

dumb question but mine is doing the same thing... whats an afm?

 

It is your air fuel ratio sensor (not sure the proper name, air fuel meter?). It is on top of your air box. Dead top center, plug is about an inch, inch and a half long I think.